Steering mechanism



March 3, 1942. I A, BLOXSOM 2,274,821

STEERING MECHANISM Filed Feb. '7, 1938 6 Sheets-Sheet 1 M a ,l l

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March 1942- I I A. P. BLOXSOM 2,274,821

STEERING MECHANISM Filed Feb. '7, 1958 6 Sheets-Sheet 2 Mamh A. P.BLOXSOM STEERING MECHANISM Filed Feb. 7, 1938 6 Sheets-Sheet 3 awe/whomMarch 3, 1942. A. P. BLOXSOM STEERING MECHANISM Filed Feb. 7, l938 6Sheets-Sheet 5 March 3, 1942.

A. P.- BLOXSOM STEERING MECHANISM Filed Feb. 7; 1938 6 Sheets-Sheet 6Patented Mar. 3, 1942 UNITED STATESv PATENT OFFICE STEERING MECHANISMAllan P. Bloxsom, Houston, Tex.

Application February 7, 1938, Serial No. 189,184

Claims.

The invention relates to improvements in steering device for automotivevehicles wherein the direction in which a vehicle is propelled iscontrolled by a hand wheel through which the planes of rotation of thevehicle wheels are controlled.

It is an object of the invention to provide coordinated directionalcontrol of the front and rear wheels of an automotive vehicle in amanner to more eifectively control the direction of travel of suchvehicle.

It is also an object to provide a device of the class described whereinsteering may be effected through the control of the direction of eitherthe front or the rear wheels of the vehicle.

Another object is to provide in conjunction with conventional steeringequipment a cooperating secondary steering mechanism for the control ofthe direction of the rear wheels of a vehicle.

Another object is the provision of novel mechanism for hydraulicallysteering a motor vehicle.

Still another object is the provision of a device of the class describedwhich gives such coordinated direction of the wheels of a motor vehiclethat a vehicle having a long wheel base may be turned in a short turningradius.

It is also an object to provide a steering mechanism in which thedirections of the wheels of a vehicle are especially coordinated forparking.

Still another object is the provision of a steering mechanism forcontrolling the direction of both the front and rear wheels of a vehicleand a foregoing will be apparent upon consideration of the followingdescription taken in connection with the accompanying drawings in which:

Fig. 1 is a plan view partly in section illustrating the use of theinvention in an automotive vehicle.

Fig. 2 illustrates constructional details in one embodiment of theinvention.

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2.

Fig. 4 is a view partly in section showing another embodiment ofmechanical construction in the invention.

Fig. 5 isa cross section taken on line 55 of Fig. 4.

Fig. 6 is a cross section taken on the line 6-6 of Fig. 4.

Fig. 7 is a view partly in section illustrating the primary steeringmechanism and the secondary steering control.

Fig. 8 is a section taken on line 88 of Fig. 7.

Fig. 9 illustrates an alternative embodiment of the primary steeringmechanism of the invention.

Fig. 10 illustrates an alternative orientation of the steering mechanismwith the chassis of the vehicle.

Fig. 11 illustrates the directional coordination of the front and rearwheels of a vehicle when using the present invention.

Fig. 12 illustrates the modified coordination in direction of the frontand rear wheels of a vehicle when the vehicle is being parked.

Fig. 13 shows the modified control assembly.

used with the construction of Fig. 4.

In the operation of automotive vehicles parking, passing other vehicles,turning sharp curves and negotiating gentle curves on the open roadpresent different problems to be solved when providing suitable steeringapparatus for such vehicles. This invention'is concerned with suchcoordination in the steering of the vehicle wheels that these problemsare solved.

In the conventional steering of a vehicle the front wheels are turned ina desired manner relative to the remainder of the vehicle through asteering mechanism under the control of the driver. Fig. 1 showing thefront wheels I as controlled hydraulically through the operation of thesteering wheel 2 and a mechanism which is herein termed a primarysteering mechanism 3. The invention includes novel structure to effectsuch steering but in order to solve all the problems of steering asabove indicated, the invention also contemplates the provision of asecondary steering mechanism 4 controlled through the steering wheel 2and which controls the direction of the rear wheels 5 in suchcoordination with the steer- I ing of the front wheels that the generalobjects of the invention are attained.

In order to clearly understand the coordination of the steeringmovements of the front and rear wheels attained by the invention,attention is directed to Figs. 11 and 12 in which the direction ofmovement of the vehicle is indicated by the arrows 25. Line segments atthe left in each figure illustrate the direction taken by the frontwheels of the vehicle while the lines at the right similarly indicatethe direction taken by the rear wheels.

Fig. 11 illustrates the conditions for ordinary This may be illustratedby reference to l driving, while Fig. 12 illustrates the conditions whenparking.

When rounding a gentle curve with conventional steering the rear wheelsdo not follow directly behind the front wheels but rather assume aposition nearer the center of the roadway than do the front wheels. Thiscondition is undesirable, particularly in vehicles having a long wheelbase as the rear end of such vehicles is brought too near the center ofthe roadway. It is therefore desirable that the rear wheels follow asnearly as possible the track made by the front wheels. Lines 26 and 21and their dotted extensions illustrate wheel directions on thestraightaway. On gentle curves the front wheels are turned from the line26 to the line 28 and at the same time it is desirable that the rearwheels be turned slightly outwardly as indicated in 29 so that the frontand rear of the vehicle will be equidistant from the edge of theroadway. Such coordination in direction of the front and rear wheelswill prevent the rear portion of the vehicle from approaching the centerof the roadway.

In encountering a curve of a shorter radius of curvature than that aboveindicated the front wheels are turned in the direction indicated by thelines 30. For such radius of curvature it is necessary that the wheelsbe turned slightly to the left in order that they will follow the frontwheels. Accordingly, the 7 rear wheels are directed as indicated by thelines 34. It should be noted that when turning within a limited radiusindicated by lines 38 and 3| the front and rear wheels are substantiallyparallel and hence the vehicle is propelled sidewardly with little or nodirectional change in the body of the vehicle.

This feature is consequently of importance When passing other vehicles.

When sharp turns are to be made it is well known that with conventionalsteering equipment the front end of the Vehicle must be directed wellinto the roadway of the new direction of travel in order that the rearend of the vehicle will remain upon the surface of the roadway. In thepresent invention this difficulty is avoided by such directionalcoordination of the rear and front wheels that the rear wheels areturned outwardly as indicated by lines 32 when the front wheels areturned inwardly on lines 33.

When parking a vehicle it is desirable that all wheels be turned in acommon direction and this condition is accomplished in accordance withthe invention in a manner to be described, whereby the front and rearwheels may be turned, when parking, as indicated by lines 35 and 35 inFig. 12.

Attention is now further directed to the mechanism of the inventionwhereby the desired results will be obtained.

Referring further to Fig. 1 it is to be noted that the steering wheel 2moves arms 5 and 5 of the primary and secondary steering mechanismrespectively to move pistons 6 and 5 in the cylinders l and 1'. Each ofthese cylinders directs fluid to one of the cylinders 8 pivotallyconnected to the vehicle frame 9 and having a piston rod l0 connected tothe steering arm I I attached to one of the wheel spindles 12. It shouldbe noted that these cylinders are arranged in pairs and that, referringfor example to cylinders I of the primary steering mechanism, when fluidis directed from one of the cylinders l to a cylinder-8, the fluid thatis displaced in the cylinder 8 is returned to the other cylinder'of thepair.

Desired coordination in the steering of the front and rear wheels iseffected by a mechanism which will now be described, such mechanismobviously being designed to effect similar coordination in movement ofthe arms 5 and 5. As is best seen in Fig. 7, the steering wheel 2 isfixed to a steering shaft 40 which is releasably connected through alocking screw 4| to a driving sleeve 42 having threads 43 thereon. Thearm 5 is provided with a collar 44 which is internally threaded tocooperate with the threads 43 on the drive sleeve 42. effects movementof the arm 5 and hence directs the front wheels of a vehicle through ahydraulic system as above described.

The lower end of the steering shaft has a reduced section 50 which isreleasably connected through a locking screw 5| to a shaft 52 whichprojects from the lower end of the driving sleeve 42 to drive thesecondary mechanism 4, an embodiment of which is shown in each of Figs.2 and 4.

Referring to the embodiment shown in Fig. 2 the lower end of the shaft52 is journaled at 53 upon the vehicle and carries a driving assemblywhich includes conical end blocks 56 which are splined upon the shaft 52and which are provided with circumferential grooves 51 to receive pins58 in a yoke 59 whereby the blocks 58 may be moved in unisonlongitudinally of the shaft 52 to serve a purpose that will be madeapparent.

Intermediate the end blocks 55 a segmented sleeve Ill surrounds theshaft and has on its periphery screw threads 61 and 58 which extend inopposite directions and join at the ends of the sleeve at 69. Suchconstruction is well known as comprising a reversible thread drive inwhich a driving block may be driven by either of the threads 61 or 68and directed to the other series of threads at the juncture point 69.

The mechanism thus far described drives the arm 5' through a drivingblock 1| fixedwithin the collar 12 integral with the arm 5. Direction ofthe driving block H within the threads 6'! and 68 is instrumental inobtaining the desired coordination of steering of the front and rearwheels.

In order to obtain the desired direction of the driving block H thesleeve H1 is broken into end segments 15 and 1B and a central segment11. Segment T1 is fixed to the shaft 52 while the end segments 15 and 16are splined thereto. These segments 15 and 16 are also connected to therespective blocks 56 and hence will moverlongitudinally of the shaftwith movement of the blocks. Cooperating with the segmented sleeves 10are pairs of complementary guiding blocks and 8| adapted to bealternatively interposed between the respective segments 15 and I6 andthe segment 11 of the sleeve Ill. The complemental blocks of each of thepairs 80 and 8| form a cylindrical segment having a thread segment asshown at 82 of th same configuration as the juncture of the threads 61and 68 at the 7 cured to the ends of arms 93 are the respective blocks80 and BI. The conical blocks 56 are slotted at 95 (see Fig. 3) to admita tension spring 95-passing through an opening 9! in, the

shaft 52 and attached to the inner ends 'of the Rotation of the sleev42' pins 9|. With this construction it isbelieved apparent that" inwardmovement of either of the conical blocks 56 will cause the associatedpins 9I to ride upon the conical surface of such block and hence tocause the accompanying guide blocks 80 or BI to move outwardly from theshaft 52. At the same time inward movement of one of the conical endblocks 56 will cause the adjacent end segment of the sleeve 10 to moveinwardly into juxtaposition with the segment 11 fixed to the shaft 52. g

In Fig. '1 is shown a steering control assembly I through which thesecondary steering assemblyA i controlled. This assembly comprisesintermeshing gears IOI, I02 and I03 to which are attached control stopsI04, I05 and I06, gear I02 being additionally provided with an arm I01pivotally connected to the rod I08. The opposite end of the rod I08 isconnected at I09 to one end of a lever H0 centrally pivoted at III onthe frame of the vehicle. A tension spring II2 attached at I09 serves tohold the linkage in a fixed terminal position when the rod I00 is movedto the right or left by the actuation of the arm I01.

Lever H0 is also shown in Fig. 2 wherein a connecting link H3 is shownas connecting the other end of the lever to the yoke 50. It is believedobvious that the position of the conical end blocks 65 is determined byactuation of the rod I08. Referring again to Fig. '7 the steering shaft40 is provided with threads I25 which engage complementary threads inthe collar I20 provided with a downwardly extended arm I21 having aprojection I28 adapted to engage the arms I04, I05 and I00 of thecontrol assembly I 00 and hence to drive the associated gears wherebythe desired actuation of the rod I08 is effected. If for example the armI21 is moved to the left, pin I28 will engage the downwardly extendingstop I04 and rotate the gear IOI in a clockwise direction to drive thegear I02 in a clockwise direction so that the rod I08 will be moved tothe left to effect a function that will be more fully described. As thearm I21 moves back to the position indicated in the drawings, gear IOIwill again be turned but in a clockwise direction by virtue of theengagement of the pin I28 with the other stop I00 which was previouslymoved to a vertical position. Such functioning will return the rod I08to its initial position. If the arm I2: is moved to the right andreturned, similar movement of the rod I08 will take place.

In the operation of the device just described it will be assumed thatthe parts are in the relative positions shown in Figs. 2 and '1. It willalso be assumed that the steering wheel is to be turned in acounterclockwise direction as viewed-from the right in each of thesefigures in order that the vehicle will be directed to the left, asindicated in Fig. 11.

Initial turning of the wheel 2 will cause the arm 5 to be moved to theleft (Figs. 1, 2 and 4) and hence the rear wheels will be directedoutwardly at an angle proportioned to such initial turning of thesteering wheel up to the point where the driving block 1I reaches thefiexure in the threaded segment 82 in the guide blocks 80. Furtherturning of the steering wheel within a limited angle will cause the arm5 to be moved to the right along the segment 15, as viewed in Figs. 1, 2and l, and hence to direct the rear wheels in the direction indicated bythe line 3| in Fig. 11. At the same time the arm I21 will be moving tothe left (Fig. '1) and the gear wheel 10 and driving block 1lfwill bedirected by the threadedsegment 82 in these guide blocks. Continuedturning of the steering wheel will carry the driving block past theflexure in the threaded segment inguide blocks BI and additional turningthereafter will then cause the arm 5' to again move to the left alongthe segment 15, as viewed in Figs. 1, 2 and l, and the rear wheelswillassume a path illustrated byv the line 32 in Fig. 11.

If the steering wheel 2 is turned. clockwise instead of counterclockwiseas just assumed, initial turning of the Wheel will direct the rearwheels oppositely to the change in direction indicated by the line 29 inFig. 11.' The arm I21 Will move to the right and projection I28 willengage control stop I05 whereupon the rod I08 will be moved to actuatethe control assembly so that guide blocks ill will be positioned betweenthreaded segments 10 and 11. As the driving block 1|. passes the flexurein the thread 82 the rear wheels will be turned oppositely to the changein direction shown by the line 3| in Fig. 11.

In a similar manner continued turning of the steering wheel will causearm I21 to engage stop I00 and gear I03 and actuate the control assemblyto place the guide blocks in the positionv shown in Fig. 2 so that driveblock II will move through the fiexure in the thread segment 82 in theseguide blocks and the direction of the wheels will be changed oppositelyto that shown by line 32. I

It is apparent that the functioning justoutlined will take place inreverse order as the steering wheel 2 is again returned counterclockwiseto bring the wheels to the straightaway position.

An alternative construction for obtaining the desired coordination insteering of the front and rear wheels is illustrated in Fig. 4 whereinthe sleeve 10 is of unitary construction, the arm 5 being provided witha. composite drive collar 12 whereby the desired driving connectionbetween the arm 5' and the threaded sleeve 10 will be obtained. In thisembodiment the collar 12 is provided with a pair of driving blocks I30and I3I, passing through radial openings in the collar 12 andinterconnected by means of semi-circular arms I32.

' The driving blocks I30 and I3I are oppositely biased and spaced sothat when the assembly is shifted to its indicated position the drivingblock I30 will be in engagement withthe thread 63 while the drivingblock I3I will be lifted clear of the sleeve 10. Theposition of theassembly I33 is determined by the control assembly I00 which as aboveindicated actuates the rod I08. In this embodiment the rod I08 isconnected to a bell-crank lever I35 having its opposite end connected bylink I36to the assembly I33. The spring I31 retainsthe assembly I33 in aterminal position until such position is altered by operation of thecontrol assembly I00,

Assembly I33 is so designed that each of the driving blocks I30 and I3Iengages its cooperating thread as the assembly is being shifted from oneterminal position to the other. Such con-. dition tends to lock thesteering assembly momentarily. The sleeve 10 is rotatably mounted uponthe shaft 52 which is provided-with pro- The assembly I33 thus formed issuch that it may be shifted transversely of the sleeve jections I40.A'spring MI is connected alternately to these projections Mil andcomplementary projections I42 internally of the sleeve I0, therebyproviding a resilient connection to overcome theinstantaneous lockedposition just referred to. l

When the embodiment of Fig. 4 is used, control assembly I is providedwith an additional gear II'II (Fig. 13) which meshes with the gear III!and which may be engaged by the projection I 28 on the arm I27 in themanner previously described. The control assembly therefore operates ina manner similar to that described in connection with Fig. 2. In thisembodiment however the two fiexures in the line illustrating the changesin direction of the rear wheels .(Fig. 11) are obtained by the coactionof the projection I28 on the arm I21 successively with the blocks I04and H34 on the gears WI and HM.

When parking the vehicle it is desirable that both the front and rearwheels be turned in a common direction in order that the vehicle will bedirected eifectively into the parking area. In order that suchfunctioning may accrue in accordance with the present invention thecontrol assembly Illil is provided with. a manually operable controlmember I 50 within reach of the driver whereby the .journal members, IIand I52 may .be moved outwardly a sumcient distance that the associatedgears IE3 and I64 will be moved from engagement with gear I05.

If then the steering wheel 2 is rotated counterclockwise to turn thevehicle to the left, the front wheels will, assume the successivepositions indicated-by the lines 26', 28', 35 and 35' in Fig. 12. Therear wheels will assume slightly different positions as indicated by thelines 21, 29, 3I' and 36. The initial departure of the rear wheels fromthe straightaway line 21' occurs as the driving block 'II approaches thefieXure in the thread segment 82 in the guide blocks 8!] while thesucceeding position 3| results from movement of the driving block lIalong the thread 69 after the flexure has been passed.

If the steering gear 2 is turned clockwise for parking to the right asthe Vehicle moves forward, the front wheels move oppositely to the lines26', 28', 35 and 35 in Fig. 12. There is a similar opposite movement ofthe rear wheels to that shown by the lines 21 29, 3i and 36, thereversal of direction between lines 29 and 3| taking place by virtue ofthe fact that the arm I21 in moving to the right (Fig. 7) engagesdownwardly extending arm I05 on the gear I02, whereby the guide blocks82 are shifted to operative r position and the driving block II causesreversal as it passes thru the flexure in the thread segment in theseguide blocks.

It is obvious that whether the steering wheel be turned to the right orleft for parking, the respective wheels are brought successively, inreverse order, thru the positions just described as the steering wheel 2is turned to bring the wheels to the straightaway position.

In event of disability of either of the steering assemblies abovedescribed, it is desirable that provision shall be made whereby thevehicle may be directed by the other assembly. To provide suchfunctioning each of the driving assemblies is attached to steering shaft49 through a releasable connection as illustrated in Figs. '7 and 8.With this construction it is believed apparent that the respectiveassemblies may be disconnected from the steering wheel 2 by releasingone or the other of the locking screws 4| and 5|.

ing spaced partitions I22 and I 23 which are aper- I tured to sealablypass a piston rod I24 carrying the pistons 6. When using thisalternative embodiment the secondary steering mechanism may beoperatively connected in any suitable manner to the steering wheel 2 forconjoint action therewith.

While the foregoing description is directed to a construction whichincludes a hydraulic mechanism for imparting steering motion to thevehicle wheels, the invention is not confined thereto as it is intendedthat such movement may be mechanically imparted from the arms 5 and 5'to cooperating mechanism for turning the wheels I and 5 about theirspindles 9. Such construction is illustrated in Fig. 10 which also showsthe major elements of the mechanism enclosed within a housing I40transversely of the vehicle frame and driven through beveled gears I4Ione of which is attached to the steering shaft 40.

What is claimed is:

l. A steering mechanism for a motor vehicle including primary andsecondary steering assemblies operatively connected to a steering wheelwhereby the relative directions of the front and rear wheels may becontrolled, said steering assemblies being constructed and arranged toturn the front and rear wheels in opposite directions when turning thevehicle on a large radius of curvature and including automatic means toturn the front and rear wheels in a common direction when turning thevehicle at a predetermined smaller radius of curvature.

2. A steering mechanism for a motor vehicle including primary andsecondary steering assemblies operatively connected to a steering wheelwhereby the relative directions of the front and rear wheels may becontrolled, said steering assemblies being constructed and arranged toturn the front and rear wheels in opposite directions when turning thevehicle on a large radius of curvature, and including automatic means toturn the front and rear wheels in a common direction when apredetermined smaller radius of curvature is reached, and to thereafterautomatically turn the front and rear wheels in opposite directions foradditional decrease in the turning radius.

3. In an automotive vehicle the combination of a primary steeringassembly for directing the front wheels of the vehicle, a secondarysteering assembly for directing the rear Wheels of the vehicle, asteering unit operatively connected to both of said assemblies, asteering wheel for driving said unit, said steering unit including meansfor actuating the primary steering assembly to turn the front wheels inaccordance with the turning of the steering wheel, and means responsiveto the rotational movement of the steering wheel from the straightawayposition for actuating the secondary steering assembly to successivelyturn the rear wheels outwardly, substantially parallel with andthereafter increasingly outwardly relative to the front wheels.

4. In an automotive .vehicle the combination of a primary steeringassembly for directing the front wheels of the vehicle, a secondarysteering assembly for directing the rear wheels of the vehicle, asteering unit operatively connected to both of said assemblies, asteering wheel for driving said unit, said steering unit including meansfor actuating the primary steering assembly to turn the front wheels inaccordance with the turning of the steering wheel, means responsive tothe rotational movement of the steering Wheel from the straightawayposition for actuating the secondary steering assembly to successivelyturn the rear wheels outwardly, substantially parallel with andthereafter increasingly outwardly relative to the front wheels andmanually operable means for controlling the operation of said last 10mentioned means to direct the rear wheels in a common direction with thefront wheels.

5. In an automotive vehicle the combination of, a primary steeringassembly for directing the

